Not the previous poster, but it seems "black" represents garbage truck whilst "green" represents recycling.
The argument they were making is if your garbage weren't going to a recycling plant, it would be going to a landfill. Either way, the same amount of waste has to be transported from your home, so the same number of trucks would still be driving around.
Recycling is a trivial number of trucks. And far as I know, they don't crush the material. Also they keep it separate (paper/glass/metal) and the sections probably never fill evenly. So a pretty inefficient operation is my guess.
That may be with the recycling operation were you live, but everywhere I have lived it's been one bin type, one truck, dump the bin and go. The only time I have had to do more than separate paper from non-paper was back when I also had to hand-carry recyclables to a drop spot.
The argument they were making is if your garbage weren't going to a recycling plant, it would be going to a landfill. Either way, the same amount of waste has to be transported from your home, so the same number of trucks would still be driving around.